Respirator



N. SCHWARTZ RESPI'RATOR iied July 2, 1957 'IINVENTOR- Patented Mar. 22, i938 UNITED, STATES PATENT OFFICE BESPIBATOB.

Nathan Schwartz, New York, N. Y. Application July 2, 1937, Serial No. 151,629

8 Claims. (01. 128-446) simplified filter unit construction wherein thick,

or thin filter material may be accommodated, and also wherein any of the materials used for filters may be mounted, such as sponge, felt, etc.

Another object is to simplify theassemblage of the filter unit.

Another object is to facilitate the cleaning of the said unit.

Another object is to'provide a displaceable filter unit, wherein any of the parts may be readily removed and replaced at little cost.

Another object is to provide a large filter area with a small air space between the filter material and its supporting wall. Another object is to provide a leak proof joint at the inlet port of the filter unit.

With these and other objects in view, the invention consists of certain novel features of construction as hereinafter shown and described 5 and then specifically pointed out in the claims.

In the drawing: i

Figure 1 is a section of the improved respiratorin applied position.

Figure 2 is a front view of the filter unit.

Figure 3 is a perspective view of the clamps.

Figure 4 is an exploded view of the several layers composing the filter unit.

Figure 5 is a modified form of the device, in section. Figure 6 is perspective view of the ring-clamp in the modified form. Figure 'Tis a back view of the filter unit in the modified form.

Figure 8 is a perspective of the plate in the second form, illustrating the edge notches. The

plate is shown partly broken.

Referring to the drawing by characters of reference, A designates the face piece of the respirator, B the filter unit, C the clamping device, D

the ring clamp device.

The face piece A is of molded elastic rubber material and is adapted to cover the noseand mouth of the wearer. It is the usual conventional type, being provided with a flutter valve, which is also of conventional type. An aperture Ill is provided in the said face piece and is located in confronting relation to the mouth and nose of the wearer.

The filter unit construction is in two forms.

The first form is illustrated in Figures 1, 2, a,

and the said washer.

and 4 and consists of a plate ll having an ape ture l2, and a central forward protrusion II. An elastic rubber washer i4 is located at the edge portionof the forward side of the said plate II. The said washer has a recess l6 and has attached thereto a wire-mesh! 5. The said attachment is secured by a proper fit between the saidlwiremesh and the said recess, which proper fit consists of a tight hold upon the edges of the .wire by the circumferentialwall of the said recess. 10 This is accomplished by having the diameter of the wire-mesh a slight degree larger than that of said recess. Filter material I1 is placed in confronting relation to the said wire-mesh A marginal ring (D) is I placed at the outer edges of the said filter material. Several resilient metal clamps C, prefer ably U-shaped are emplaced peripherally. Five such clamps are distributed evenly at the said periphery, whereby a leak proof joint is provided thereat, due to a squeezing action of the said clamps upon the edges of the plate II and upon the saidv ring (D). That is. the said clamps are emplaced overlapping the said edges and the said ring and due to its comparative narrow size and its resiliency, it provides a compression upon the said parts and thereby causes aleak proof peripheral joint. I

The aperture l2jis connected with the aperture Ill by means of an eyelet 20, whereby communication is established between the face-piece of the respirator and the filter unit.

It will be noted that the wire-mesh acts as a support for the filter material. An air space II is formed between the plate I I and the wire-mesh IS. The central protrusion 13 aids to maintain the said space. Space formation in this manner has several distinct advantages. The firmness of the wire-mesh under all conditions of moisture or fumes provides a constantly uniform space. .40 That is, there is no diminution of the space due to possible sa'gging of the filter material; such sagging may occur in felt, cotton, or sponge material when unsupported.- Also, a comparatively small air space may thus be maintained: 4:; minimizing the reinhalation of' exhaled air. When corrugations of the plate are utilized for. maintainingjan airspace, the numerous contacts with the filter material provide an impediment to the free fiow of air. Therefore, breathing is 50 easier in the present arrangement. Another advantage is that a sponge filter may be used with a chemical neutralizing solution added thereon with the wire-mesh support arrangement herein described. Attention is called to the washer ar- 55 aids the formation of the said air space at the marginal area. I

The second form of this invention is illustrated in Figures 5, 6, 7, and 8. The plate Ila has an aperture l2a, a central protrusion l3a, and a marginal curve l9 which is directed forward and outward. The aperture l2a of the plate connects with the aperture Ill of the face-piece A of the respirator. An eyelet 20 is used to make the said connection, whereby communication is established between the face-piece and the filter unit. Filter material I! is mounted between the edges of the plate Ila and a ring-clamp 2!. A wire mesh lie is placed at the rear side of the filter material and it abuts the marginal end IQ of the plate Ma and it also abuts the protrusion l3a whereby a space l8a is formed.

The elastic rubber washer is not shown in this form, but it may be adjusted in the manner described in the first form. But this form is quite practical without it, especially so if the respirator is used in light duty work.

The ring 2| is preferably of a substantial, rigid, metallic construction and preferably wire shaped. It has attached by means of solder six resilient wire prongs 22 which extend rearward. Three notches 23 are provided at the inner side. The circumferential diameter of the prong area is less than the plate area. However, due to the resiliency of the said prongs, they are slipped over the edge 24 of the plate I la with ease. The edges 24 are provided with notches 25. The positions of the notches 25 correspond to that of the prongs 22. The prongs 22 are therefore positioned to embed in the said notches 25 and when the said embedding is adjusted at the notches 23, an interlocking arrangement occurs. That is, the prongs are fastened, or anchored, and cannot move forward, backward, nor sidewise.

A wire span 26 is located at the rear side of plate lla which is for the purpose of providing additional firm support for the ring-clamp. As illustrated in Figures and 7, the wire span 26 is wound about the rear portion of the prong 22.- That is, the wire is wound around two prongs located opposite each other. While the wire is intact the ring clamp is not removable. However, the filter material and its wire mesh support are removable. The method of attaching wire spans are simple; one end of the wire is wound at the rear portion of a prong 'and the other end of the wire is wound to the rear portion of an opposite prong with a moderate degree of tightness. To make the ring-clamp removable'for cleaning or replacement purposes, the wire must be removed first. If desired two or three such wire spans may be applied. That would add greater security to the firmness of the structure and would be required only in extremely heavy duty work If additional wires are added, they are to be applied as per description for the one wire attachment.

It is to be noted that the filter material is removable in the second form without removing any other part of the filter arrangement. That is, the clamp arrangement is such that it remains intact without a filter material inclusion. Therefore the used filter material may be removed and a new one inserted. The removal is practical by a direct pull from without or by pressing thereon from within through the aperture l2a.

It is to be noted that the U shaped clamps C are shown as having a short and a long arm and as rangement. It is readily seen that the washer a wide U with rather short arms. However, in practice the size and shape may vary to suit the precise needs, for example, a substantially V shaped clamp may at times be more readily adjusted than a U shaped one.

It is also to be noted that the U shaped clamps C may be permanently attached to the ring-clamp D by means of solder. This arrangement may be preferred when greater firmness of the clamping arrangement is desired for heavy duty work. One clamp C is illustrated so attached in Figure 4. In this manner of clamp arrangement, the filter material may be removed independently of the rest of the marginal layers, and a new one inserted thereat.

It is to be noted that cleanliness of the filter unit marginal portion is easily maintained in the improved device, because the clamps and all parts of the marginal layers are displaceable and replaceable. Advantages of the older methods therefore are obvious, namely, when threading devices are-used in plants where chemical fumes are present, such devices may erode and thereby permit leaks at the filter material marginal attaching joint. When grooves are utilized for filterattachments, dirt may accumulate thereat. In paint, shellac, glue, varnish and plaster works where the substances are sticky, the cleaning operation is difilcult. Inwoolen works anthrax or other germs may collect in the grooves or in the threads, and antiseptic applications are not easy to apply, while in the improved displaceable device herein described such antiseptic applications may readily be applied to every portion of the said marginal layers of the said filter unit.

It is to be noted that the elastic rubber washer has a very important function in the improved respirator. Its elastic compressibility provides a needed function, namely, to choke and seal the joint between the filter material and the metallic plate edge. The action is caused by the function of the said elastic rubber in filling in irregularities contained in the metal and also in the filters.

All metals and filter elements have irregularities. If they have none, they soon obtain some while in use. The extraneous substances in the workshop are usually such as to attack the metal or the filter element and thereby cause irregularity in the filter element and erosion or irregularity in the metallic edge.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A filter unit for filter type respirators, in-' cluding a plate, filter material mounted in confronting relation to the said plate and spaced therefrom, and clamping means comprising a marginal circumferential ring located at the outer edges of the said material, the said ring having a plurality of prongs attached thereto, which prongs are connected to the marginal portion of the plate, whereby the edge of the said material is squeezed between the edgeof the said plate and the said ring.

2. A filter unit for filter type respirators, including a plate, filter material mounted in confronting relation to the said plate and spaced therefrom, a circumferential ring disposed at the outer edges of the said material, and clamping means comprising several substantially U shaped clamps attached overlappingly to the edges of the said plate and to the said ring, whereby the edges of the said material are squeezed between the edges of the said plate and the said ring.

3. A filter unit for filter type respirators including a plate, filter material removably mountaiiipot ed in confronting relation to the said plate and spaced therefrom, and clamping means comprising a marginal circumferential ring disposed at the outer edges of the said material, and the said ring has means to secure it to the edges of the said plate whereby the said ring impinges upon the edges of the said material and thereby providing a leak proof joint between the edges of the said plate and the said ring, and maintaining the periphery of the said material in a substantially uncovered position.

4. A respirator, a face-piece having an inlet port, a filter unit, having a plate with an aperture, filter material mounted in confronting relation to the said plate and spaced therefrom, and clamping means including a circumferential ring disposed at the outer edges of the said material and the said ring having means to attach it to the edges of the. said plate whereby the said ring impinges upon the edges of the said material and thereby providing a leak proof joint between the said ringand the edges of the said plate, the

periphery of the said material being substantially of the saidmaterial and the said ring having means to secure it to the edges of the said plate whereby the edges of the said material is impinged upon by the said ring, securing the said material between the said ring and the edges of said plate, and the said material confronts the said plate and is spaced therefrom by the said foraminous supporting element, which element is interposed between the said material and the said plate and abuts the said protrusion.

6. A filter unit for filter type respirators including a plate, a washer, and filter material mounted in confronting relation to the said plate and spaced therefrom by the said washer, a circumferential ring disposed at the outer edges of the said material, and clamping means attached to the said ring and to the edges of the said plate, whereby the said ring is caused to squeeze the said filter material at the edges thereof directly against the said washer and thereby form a leak proof joint thereat.

7. A filter unit for filter type respirators, including a plate, filter material mounted in confronting relation to the said plate and spaced therefrom, a circumferential ring disposed at the outer edges of the said material, a plurality of prongs attached to the said ring and means to secure the said prongs to the edges of the said plate in a manner whereby the said ring impinges upon the edges of said material, thereby forming a leak proof joint thereat, with the pherlphery of the said material being in a substantially uncovered position.

8. A filter unit for filter type respirators, including a plate, filter material mounted in confronting relation to the said plate and spaced therefrom, a circumferential ring disposed at the outer edges of the said material, a plurality of prongs attached to the said ring and to the edges of the said plate, and a wire span fastener attached at the rear end portions of opposite prongs and disposed at the rear side of the said plate, thereby providing firm support for the said prong attachments to the edges of the said plate.

- NATHAN SCHWARTZ. 

